A magnetic recording medium comprising a non-magnetic support having thereon a magnetic layer containing ferromagnetic particles uniformly dispersed in a binder is conventionally and widely used as a video tape or an audio tape. Recently, with improvements in the high image quality of home VTR's, improvements in high image quality of a video tape used therein has also been demanded. The resolution of image is limited in the recording and reproducing system wherein the conventional Y signal carrier frequency is from 4.4 to 4.8 MHz. In this connection, it has been proposed to increase the Y signal carrier frequency to such an extent that there is reciprocity with the conventionally known carrier. However, the Y signal carrier can be increased only by 1 MHz, and thus brings about an insufficient improvement of the resolution.
Further, when the Y signal carrier frequency is increased to 6 MHz or more to increase the resolution, a sufficiently high output could not be obtained due to self-demagnetization in the conventional video tape having a coercive force of from 600 to 700 Oe. For the above reason, the above high output can be obtained by adjusting the coercive force of the video tape to 800 to 1000 Oe. But in this case, recorded signals can not sufficiently be erased by a conventional erasure head. And when erasure current is increased with a conventional erasure head to overcome this problem, there is a further problem that the erasure rate is deteriorated due to heat generated from the head.
Unless both an average length in the long axis and a crystallite size of the ferromagnetic particles in the magnetic layer are reduced, noise increases although sensitivity is improved, and as a result, there is also a problem that image quality of the reproduced images is not improved.